Pyongyang has developed a number of sophisticated ways to get around UN sanctions on illegal weapons trading.
A UN report, issued on Tuesday as part of an annual accounting of North Korea's compliance with international sanctions, says that North Korea's embassies in Cuba and Singapore are suspected of facilitating illegal arms deals.
The report adds that there's a relatively complex "corporate ecosystem" of foreign-based firms that helped the regime evade scrutiny of its financial dealings.
The report cited an example of a contract by North Korea's national carrier, Air Koryo , to purchase new jetliners in 2012.
It said more than 1-hundred payments were structured through eight Hong Kong-registered companies.
While the purchase of civilian aircraft is not prohibited under UN sanctions, the report says such unusual activity could be used as a test run for illegal transactions.

Officials at Seoul's Foreign Ministry have said South Korea will seek steps to implant sanctions against North Korea.
Under numerous UN sanctions, Pyongyang is restricted from shipping and receiving cargo related to its nuclear weapons and missile programs.
Importing luxury goods and illicit transfers of cash are also prohibited.
Shin Se-min, Arirang News.